As the Chicago Bears prepare for the start of rookie camp Friday, they continue to get rookies under contract.

The latest in the fold is second-round linebacker Jon Bostic, who agreed to a four-year deal Thursday, according to a team announcement.

The signing of Bostic leaves first-round pick Kyle Long as the only unsigned rookie on the team. The Bears previously had signed fourth-round linebacker Khaseem Greene, fifth-round offensive tackle Jordan Mills, sixth-round defensive end Cornelius Washington and seventh-round wide receiver Marquess Wilson.

Bears vice president of football administration Cliff Stein is known as one of the most efficient negotiators in the league, and he typically moves quickly to get deals done with rookies.